"Ivy league" or "American natural shoulder".

The so called style "Ivy League" (coat with natural shoulders,undarted,lack of waist suppression..or very few..single center vent,flat front trousers) was realized bespoke for many decades in several temples of this style: Brooks Brothers,Langrock,JPress,Chipp,The Andover Shop,and others).

By looking at this (again) I'd say that you are good to go with any Tailor and Cutter draft from the post WWII era.

Which basically means that you can ask any of your Italian tailoring friends, since the Italian systems are a lot like the British systems. Just skip the front dart.

"Nur der ist Meister seiner Kunst, der immer sucht, das Gute zu verbessern und niemals glaubt, das Beste schon zu haben.""Only he is a master of his art who always seeks to improve the good and never believes to have the best already"